Method of hydrocarbon oil conversion



Patented Aug. 9, 1927.

UNITED STT s LYMAN C. I-IUFF, OF CHICAGO, ILLINOIS,

ASSIGNOR TO UNIVERSAL OIL PRODUCTS COMPANY, OF CHICAGO, ILLINOIS, ACORPORATION 0F SOUTH DAKOTA.

METHOD OF HYDROCARBON OIL CONVERSION.

Application lled November This invention relates to improvements inmethod of hydro-carbon oil conversion, and refers more particularly tothel subjection of hydro-carbon oil of low Baume gravity to convert sameinto a range of products which have a higher gravity and which have aWider commercial market, such, for instance, as gasoline, kerosene andthe like. f The specific embodiment of the present invention resides inheating the oil to a conversion temperature to cause substantialvapor-ization; in separating the vaporized portions from the unvaporizedportion, and separately withdrawing same; in then mixing together theunvaporized and vaporized portions previously separated, and passing thecombined mixture to a bulk supply where'y` the vaporizable portionsstill existent in the heated bulk supply will separate and may bedephlegmated and condensed, in the usual manner.

As a feature of the invention, a predetermined pressure is maintainedlon the oil and vapors during the heating period and also during theperiod when the iirst separation of vapors from non-vaporizable residueltakes place. The pressure may be then reduced, and by proper regulationin the second separating stage will result in the production of aresidue controlled as to its viscosity an consistency and having a rangefrom a sub-l stantially liquid residue containing suspended coke-formingarticles down to a substantially solid residue consisting of a coke-likemass having substantially no liquid residue therein.

Other features and advantages of the process and apparatus will beapparent from the following description.

The single figure of the drawing is a diagrammatic side elevationalview, Vpartly in vertical section, of apparatus for carrying outthe'invention.

Referring more particularly to the drawing, 1 designates a side redfurnace of a standard. type of commercial installation now on themarket, provided with the combustion chamber 2, baille 3 and tube cham`ber 4. The burners 5 generate gases lof combustion within the chamber 2,passing through the iiues 6 in a downward direction through the tubechamber 4, being exhausted at the point 7 to a suitable stack. The rawoil may bel f ed from any suitable source into the pipe 8, and said rawoil may bepassed 18, 1 925. Serial No. 69,736.

directly to the heating coil 9 through the pipe 10 by opening the valve11, or it may be diverted and either all or a portion of the raw oilcharge fed through the line 12, controlled by valve 13,` into the upperend of lthe dephlegmator 14. This dephlegmator 414 may be of anystandard form suitable for installations of this character and need notbe described in detail. The raw oil charge is heated in the continuousheating coil .9 to conversion temperature and is transferred, by meansof the transfer line 15 controlled by valve 16', to an enlargedexpansion chamber 17. This expansion chamber 17 is preferably amheatedand is, therefore, covered with any siutable form of lagging orinsulation designated 18. The chamber maybe provided with the usualupper and lower manhole plates 19 to facilitate cleaning.

The heated oil being introduced to said chamber through the transferline 15 separates into vapors and a heated unvaporized residue. Thevapors may be withdrawn through the vapor line 20 controlled by valve21, while the unvaporized residue may be discharged through the residuedraw-olii' line 22 controlled by valves 23. An auxiliary valve 24 in thevapor line 2O is closed, and a valve 25 in the line 26 is opened. The

d line 26 communicates with an enlarged chamber 27, which may be similarto the enlarged chamber 17 in design. The liquid residue draw-oft' pipes22 communicate with a pipe 28 controlledby valve 29, which pipe 28communicates in turn with the vapor communicating pipe 26. The valve 30in the pipe 28 may be closed.

It is obvious, from the fore oing description, that the vapors separatein the chamber 17 have been remixed with thevunvaporized'portionwithdrawn from the chamber 17, and this mixture passed to the chamber27, where a further separation takes place. The purposes and advantagesof this willl be subsequently. described.

The vapors released from the highly heated hydrocarbon mixture in thechamber 2 7 are passed into the lower 14. In the dep legmator 14, the.vapors are 's'ubiected to suitable cooling mediums, and their upwardtravel is retarded in the usual way. rThe vapors which remainuncondensed after passing through the dephlegthrough the vapor outletpipe 31` controlled by throttle valve 32, discharging portion ofthe'dephlegmator mator pass out through the vapor outlet pipe A33, inwhich is .interposed throttle valve 34, discharging into the condensingcoil 35'sea-ted in condensing box 36,' and'the condensed product iscooled in the receiver 37 which is provided with the gas relief pipe.38, controlled by Valve 39, and with the iquid draw-off pipe 40,controlled by v alve 41.` Thereceiver 37`is preferably provlded with theusual sight gauges, pressure gauges and the like. In case it should bedesirable to return acertain portion of the condensed distillate mfromthe receiver 37 to the dephlegmator forcooling purposes, or to any partof the System, the Valve 41 may be partially closed andthe valve 42 inpipe 43 is opened, saidl pipe 43 being connected to the system. It mayalso be desirable to divert and return a portion of the incondensablegas, which may be accomplished by manipt ulating the valve 44 in theline 45.

Therefiux condensate from the dephlegma-tor 14 may be Withdrawn from thereflux leg 46, in which is interposed valve 47, to the line 48,controlled by throttle valve 49. Av

The charging stock, withdrawn from any suitable storage, may be forcedinto the line 8 and may be heated in the heating coil 9 to a conversiontemperature; for instance, the transfer temperature may be, say, from700 to 950 F. more or less. The lighter fractions of the heated oilbeing discharged into the chamber 17 will vaporize, said vapors being4withdrawn through the vapor outlet pipe 20. The unvaporized residue iswithdrawn through the pipes 22, and the vapors and residue mixedtogether again at the point X., this mixture then discharging into thechamber 27. A pressure of from three pounds above atmospheric to severalhundred pounds may be maintained on the oil being heated and on theheated hydro-carbon constituents in the chamber 17, but it is preferableto maintain this pressure above, say, 35 ounds'. `Through ropermanipulation lo thevalves 29 and 5, the pressure on the mixture beingintroduced to the chamber 27 may be materially reduced; for instance,the chamber 17 may be maintained under a pressure of, say, 200 pounds tothe. square inch more or less, which pressure may be reduced to, say 100pounds to the square inch in the chamber 27 lt' is a well knownprinciple in the treatment of hydro-carbon oils that the reduction ofpressure maintained on a body of\heated hydro-carbon oil will causevaporization of a portion of the Volatile fractions existent in saidhydrocarbon oil body due to the latent heat of said body and thereduction of pressure. This is one of the principles which is utilizedin the present invention, in combina- `tion with other novel features.

It will be immediately apparentl that by the proper regulation ofthetemperature at which the oil. is originally heated and the extent ofpressure reduction in the second chamber, the vaporization may becontrolled to a nicety. Thus it will also be apparent that it ispossible to control the viscosity or qualit of the unvaporized residueremaining in t e chamber 27 after the desired proportion of vapors havebeen relieved. By controlling the temperatures and pressures, theresidue'inthe chamber 27 may range in viscosity and consistency fromasubstantially liquid unvaporized residue, containing precipitatedcarbon particles, to a substantially solid, coke-like residue, con#taining a minimum of liquid residue.\ Of

course,l it is, to be understood that a liquid level is maintainedwithin the second chamber and also that the second chamber is preferablyexternally unheated.

The present invention has been perfected to supply the need ofrefineries which wish to have a plant which is flexible enough toproduce either a maximum yield of light gravity commercial products,such as gasoline and the like, with a minimum produc# tion of liquidresidue, at low fuel costs, as well as a plant in which it is possibleto produce an average yield of lighter gravity commercial products andat the same time roiet l duce a liquid residue which can be utihzed forfuel. The mixing of the heated vapors and -unvaporized heated residuefrom the first chamber and injecting the mixture into the second chamberat a lower pressure will have a beneficial effect on the liquid residuewhich is withdrawn from the second chamber, making it more stable andless liable to precipitate carbon particles when subsequently used, forinstance, as a fuel oil?y It is obvious, of course, that if the head ofreflux condensate is high enough to overcome the reduction of pressure,the pump 50 may be dispensed with. The second chamber 27 may take theform, as desired, of an optional cokinV chamber, or an ordinary exansion chamer. I have shown two cham ers 17 and 27 connected in series.lt is obvious,

of course, that any number, or any style, of

chambers may be utilized without departin from the spirit of the presentinvention an further, that external heating may be applied if founddesirable.

"l claim as my invention:

1. A process for cracking hydrocarbon oil, consisting in raising the oil-to ya cracking temperature while flowing in a restricted stream througha heating coil positioned in a furnace, in collecting a body of rtheheated oil, subse uent to its passage through the' heating coil, inA anenlarged reaction zone, wherein conversion occurs, in separatelyremovingzthe vapors evolved from the oil and unvaporized liquid oil fromsaid reaction zone, in admitting said vapors and unva orized liquid o1lin said zone of re-v duce pressure, in a commingled state, to refluxcondensation, in aiding in the reflux condensation of the vapors by.employing charging oil for the process as a cooling medium therefor andto also preheat the charging oil, in collecting a supply of. commingledreflux condensate separated from the vapors 'and preheated charging oilin a zone out of contact with unvaporized li uid oil introduced to saidzone of reduce pressure, and in continuously admitting oil from saidsupply to said heating coil.

f 2. A process for cracking hydrocarbon .1 oil, consisting inmaintaining a body of oil under cracking conditions of temperature andpressure in an enlarged zone, in removing vapors evolved from the oilfrom, such enlar ed zone, in separately removing the heate unvaporizedliquid oil from said enlarged zone, in introducing the vapors and theunvaporized 'liquid oil. removed from said enlarged zone to a zonemaintained under a lower pressure than said enlarged zone, wherein avaporization of substantial quantities of such unvaporized liquid oil is.effected by the contained heat thereof, in

removing the unvaporized oil from'said zone maintained under said lowerpressure without again returning the same to said zone, in subjectingall the vapors evolved from the oil in both of said zones to a refluxcona stream of commingled charging oil and reflux condensate from saidsupply through a heating coil, wherein the same is raised t0 a crackingtemperature, and in thereafter admitting said heated stream ofoil tosaid` body of oil maintained in said enlarged zone. 3. A process forcracking hydrocarbon oil, consistingin raising the oil to a crackingtemperature' While flowing in a -lstrealn through a heating coil, indelivering the heated oil, subsequent to its passage -through theheating coil, to an Aenlarged reaction zone, in separately removing vaJors evolved from` the oil and unvaporize liquid oil from said reactionzone, in materially reducing the pressure on the unvaporized liquid oilremoved from said reaction zone, to cause substantial quantities of suchoil to vaporize by latent heat thereof, isolating the oilV unvaporizedby said reductionin pressure from the process, in subjecting the vaporsreleased from such unvaporized oil, together with vapors removed fromsaid enlargedreaction zone, while in a commingled state, to refluxcondensation, in continuously passing the reflux condensate separatedfrom such commingled vapors undergoing reflux condensation, togetherwith incoming charging oil for the process, through said heating coil.

4. A continuous process for cracking hydrocarbon oil,.comprising raisingthe oil to a cracking temperature while flowing in a restrictedtstreamthrough a heating coil positioned in a furnace, delivering the heatedoil from said coil to an enlarged reaction zone, wherein conversionoccurs, maint-aining a superatmospheric pressure on the oil 'in saidcoil and reaction zone, separately removing vapors evolved from the oiland unvaporized liquid oil from said reaction zone, releasing thepressure on the unvaporized liquid oil removed from said reaction zone,to efl'ect further vaporization thereof by latent heat of saidunvaporized liquid oil, isolating that portion of the heavy unvaporizedoil which does not vaporize under the reduced pressure from the process,subjecting the vapors evolved from the unvaporized oil, due to suchrelease of pressure, together with vapors removed from said reactionzone, whlle in a commingled state, to reflux condensation, under apressure not in excess of the pressure maintained on the( unvaporizedliquid o il subsequent to its removal from said' reaction zone, unitingcharging oil for the process vwith reflux condensate separated from saidcommingled vapors undergoing reflux condensation, and supplying theresulting mixture to said heating coil.

5. A continuous process for cracking hydrocarbon oil, comprising raisingthe oil to a cracking temperature while flowing through a heating coildisposed within a furnace,

delivering the heated oil, subse uent to its passage through the heatingcoi to an enlarged reaction chamber, maintaining a superatmosphericpressure on the oil in the coil and reaction chamber, separatelyremoving vapors and unvaporized liquid oil from the reactioncha-mbenfdelivering such removed vapors and unva orized liquid oil to acommon zone maintalned under a substantially lower pressure than ismaintained in said reaction chamber, and wherein substantial quantitiesofthe unvaporized liquid oil removed from said Areaction chamber arevaporized by .the latent heat of such unvaporized liquid oil, subjectingthe vapors removed from said reaction chamber,ytogether with va orsreleased frm.,.said uilvaporized liqui oil in said common zone,

to reflux condensation, under a pressure not'l in excess of the pressuremaintamed in said common zone, removing the unvaporized residue fromsaid common zone without again vadmitting the same tothe oil undergoingtreatment in the process, and supply'- ing the reflux condensateseparated from said commingled vapors, together with charging oil, tosaid heating coil.

. y LYMAN C. HUFF.

